Most folks tend to define athleticism primarily as explosiveness, yes. In this sense, things like size, weight, or isometric strength are not 'athleticism'. But a problem comes when you equivocate 'has less athleticism' with 'is more technical'. When, for instance, the ability to get a convenient handhold on any part of the opponents body allows you to impose size, weight, and strength advantages over an opponent to much greater degrees than would be possible without them. Hence situations are created where something is not 'athletic', but also not 'technical' either. Do you see the issue now?
It's this selective application of criteria for 'technicality' that is taken issue with, highlighting attributes more relevant for success sans kimono, while attributes more relevant for success with jammies are left as rhetorical blindspots.
Look I've already argued about this extensively in the S/C forum on this site lol...I don't care to argue it anymore.
For me and what I think is close to the "correct" objective truth to define athleticism is this:
Strength is a part of it. Endurance/Cardio is a part of it. But both are on the polar end of the spectrum of "athleticism". So it's hard to really define someone as athletic for being good to very good in that extreme end.
For example - Would most people consider Eddie Hall athletic? Or a Kenyan marathon runner with world class times but looks like a concentration camp survivor? Like sure, on some level top powerlifters and top endurance "athletes" are athletic. But then we can just break it down into super specific, niche categories and call anyone athletic.
So then is a ping pong player athletic because they have amazing hand eye coordination and reflexes? Is a guy who can close the captain of crush 4 or grip a lapel like no other but is terrible at running, jumping, moving, everyone else...some athletic specimen? I just disagree. It becomes abusrd and childisih at a point.
Yes strength matters, yes cardio matters. Both matter a lot in fighting and grappling. But having good cardio or being strong doesn't make you "athletic" per se. They are just both parts of the puzzle and most would consider them minor parts. Another reason is that they are
highly trainable where as other more classical athletic things (classical for a reason...) are NOT very trainable at all i.e. sprinting, jumping, change of direction/agility, getting int power output even.
So no I'm not going to acknowledge every little niche physical attribute that a human can perform as being inherently "athletic". In a literal sense maybe you can, but it's just absurdity at that point. Playing guitar really fast has to be athletic then...and if we're having a serious conversation about athleticism that would be a retarded point to make.